This project was designed to evaluate the potential use of Macaca nemestrina as an in vivo model for human hepatitis C infection. Two adult macaques were inoculated intravenously with human serum from a hepatitis-C-infected patient. After the macaques were determined to be negative for hepatitis C, a second inoculation was performed (week 25 after the first inoculation) with a "cocktail" of serum from five human patients positive for hepatitis C. This project was terminated at 41 weeks after the initial inoculation, after the macaques had been determined to be negative for hepatitis C by all available standard blood tests and bone marrow evaluations. The macaques were euthanized and blood and liver samples were collected for histopathological examination.